Olynyk scored 25 points in 27 minutes in Boston’s 95-88 loss to the Magic, dazzling the Amway Center crowd of NBA executives, coaches, and media with an array of scoop shots, hook shots, short jumpers, and 3-pointers. He made 9 of 12 shots, including 2 of 4 from long range.

The rookie also grabbed seven rebounds during his first pseudo-NBA game.

Above all, Olynyk looked smooth. He displayed strong ballhandling skills that date to his days as a point guard before a high school growth spurt turned him into a center. He also flashed some nice range on his shot and above-average court vision.

But the main criticism of Olynyk from his teammates and coaches was that he wasn’t aggressive enough, namely by turning down open shots to pass instead.

“He needs to know that we have the utmost confidence in whatever decision he makes because he’s such a smart basketball player,” said Celtics assistant Jay Larranaga, the head coach of Boston’s summer league team.

Forward Jared Sullinger didn’t play as he is recovering from back surgery, but he sat on the bench and was as vocal as most of the coaches — and he was especially vocal toward Olynyk.

“Kelly’s a great basketball player, as you can see,” Sullinger said. “He has the inside game, outside game. I just feel like he has to be more aggressive. Especially in the summer league right now. Every time he touches, he should look to score, and the open shots, he’s got to shoot them.”

Said Olynyk, “It’s tough, because I think I’m kind of an unselfish player. They’re telling me to shoot the ball when I’m open and not worry. I’ve got to work on that and hopefully I’ll have a couple days here to get in that mode.”

When Celtics president of basketball operations Danny Ainge introduced Olynyk after the draft (he signed his contract over the weekend), he spoke of him as a player the Celtics would like to spend more time on the perimeter than down low, and one they’d like to be a proficient 3-point shooter.

Olynyk made his first two shots from 3-point range and said it’s been an area of focus for him “because it’s a real asset to a team to have that, to have a big that can stretch the floor.

“It opens up driving lanes for the guards and makes it tough on the defenses. It’s something I’m really focusing on. I’m by no means where I need to be.”

Several times during the game, an Orlando defender backed off and gave Olynyk space to shoot. He said that wasn’t necessarily because they didn’t respect his shot.

“It’s different for big guys to guard you out there,” he said. “Sometimes it’s not that they’re giving you an extra cushion because they don’t think you can make it, it’s just because it’s not natural.”

Beyond that, Olynyk, who is close to 240 pounds, also has to adjust to the physical nature of the NBA — a change any player new to the league has to make.

“I knew it was going to happen, I expected it,” he said. “It didn’t catch me off guard. You’ve just got to hold your guard, not back down, and be yourself, but obviously I was a little bit too physical, maybe.”

And by being a little bit too physical, Olynyk meant he was fouling too much. He had six Sunday. Thankfully for him, players can’t foul out of summer league games.

But Larranaga also praised Olynyk’s versatile skill set.

“Kelly is very, very skilled,” Larranaga said. “He can shoot, he can pass, he can dribble. He plays defensively, he talks. Maybe one of his biggest strengths is how well he talks the game and stays connected to his teammates.”

New Celtics coach Brad Stevens, who is noted for a high basketball IQ, watched from the sideline and came away impressed by Olynyk.

“I really like his game,” Stevens said. “He’s really bright. You can tell he makes others around him better. I thought he did some good things defensively as well. He’s going to be a good player.”

Second-year center Fab Melo struggled in the first half but finished with 9 points and 8 rebounds in a team-high 28 minutes. Forward Tony Mitchell scored 16 points and guard Phil Pressey added 11 off the bench. Center Colton Iverson, whom the Celtics chose in the second round of the draft, went scoreless and grabbed four rebounds in 16 minutes.

Guard Nolan Smith, who is playing with the Celtics’ summer league team, suffered an undisclosed lower right leg injury that he said probably will keep him sidelined during the rest of the schedule in Orlando.